CVE-2026-24032

High

Published: 14 April 2026

Published

14 April 2026

Modified

17 April 2026

KEV Added

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Patch

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CVSS Score 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS Score 0.0004 11.5th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-24032 is a high-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 11.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 IA-2 (Identification and Authentication (Organizational Users)) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

IA-2 Identification and Authentication (Organizational Users) good match

prevent

Requires systems to identify and authenticate organizational users before granting access, directly addressing the insufficient validation of user identity that enables authentication bypass.

SI-2 Flaw Remediation good match

prevent

Mandates identification, reporting, and correction of flaws like this authentication weakness, enabling application of the Siemens patch to eliminate the vulnerability.

AC-3 Access Enforcement partial match

prevent

Enforces approved access authorizations in accordance with policy, providing a secondary layer to limit damage from unauthorized access gained via authentication bypass.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Remote unauthenticated auth bypass in public-facing app directly enables T1190 for initial access.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A vulnerability has been identified in SINEC NMS (All versions < V4.0 SP3 with UMC). The affected application contains an authentication weakness due to insufficient validation of user identity in the UMC component. This could allow an unauthenticated remote attacker…

to bypass authentication and gain unauthorized access to the application. (ZDI-CAN-27564)

Deeper analysisAI

CVE-2026-24032, published on 2026-04-14, is an authentication weakness in the UMC component of SINEC NMS, affecting all versions prior to V4.0 SP3 with UMC. The vulnerability arises from insufficient validation of user identity, classified under CWE-347, and carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

An unauthenticated remote attacker can exploit this vulnerability over the network with low complexity and no user interaction required. Successful exploitation allows the attacker to bypass authentication and gain unauthorized access to the application.

Siemens has issued Security Advisory SSA-801704, available at https://cert-portal.siemens.com/productcert/html/ssa-801704.html, addressing this issue (ZDI-CAN-27564).